New analytical tools and smartphone-based devices exploiting cell-based and bioluminescence detection for environmental and diagnostic applications

The use of portable light detectors and smart supports and bioinspired materials to confine living cells and use them for field-deployable biosensors has recently attracted much attention. In particular, bioluminescent whole-cell biosensors designed to respond to different analytes or classes of analytes have been successfully implemented in portable and cost-effective analytical devices. The activity carried out during my PhD was mainly focused on the development of whole-cell bioluminescent (BL) biosensors for multi-analyte detection and their implementation into portable analytical devices for point-of-care and point-of-need applications. Thanks to the high maturity level of reporter gene technology and the availability of several bioluminescent proteins with improved features, bioluminescence smartphone-based biosensing platforms were developed exploiting highly sensitive luciferases as reporters. A 3D-printed smartphone-integrated cell biosensor based on genetically engineered human cell lines was developed for quantitative assessment of toxicity and (anti)-inflammatory activity with a simple and rapid add- and-measure procedure. Moreover, since cells in 2D cultures do not often reflect the morphology and functionality of living organisms, thus limiting the predictive value of 2D cell-based assays, we implemented 3D cell-based assays. A non-destructive real-time BL imaging assay of spheroids for longitudinal studies on 3D cell models was first developed exploiting micropatterned 96-well plate format. The assay performance was assessed using the transcriptional regulation of nuclear factor K beta response element in human embryonic kidney cells. The assay can be implemented in any laboratory equipped with basic cell culture facilities and paves the way to the development of new 3D bioluminescent cell-based assays.